The liquid crystal display (LCD) has been widely used in various electronic products, most of the liquid crystal display are backlight type liquid crystal display including the display panel and the backlight module. According to the incident position of the light source, the backlight module can be classified into the side-light type and direct-light type.
The backlight module typically includes a light source and a light guide plate; In order to guarantee the display effect of the liquid crystal display, it needs to keep a stable optically coupling distance between the light source and the light input surface of the light guide plate. Because the internal space of the backlight module is sealed, it is difficult to carry out the convection of the internal air with the external air. Therefore, when the backlight module is used, the temperature of the light source is higher, especially the light source of the side-light type backlight module. Thereby, the temperature of the light input surface of the light guide plate close to the light source is also higher. It causes the light guide plate to easily generate substantial thermal expansion, warpage and other structural variations, so that the distance between the light source and the light input surface of the light guide plate is changed. Thus, the display effect of the liquid crystal display is affected.
In order to reduce the deformation of the light guide plate caused by the temperature rise of the light source, people try to produce suitable heat sinks to reduce the temperature of the light source; however, the manufacturing cost of the backlight module will be greatly increased.
Therefore, it is necessary to provide a backlight module and a liquid crystal display device to solve the problems of the traditional technology.